These two volumes provide the Arabic, Latin and English text of the major work on historical astrology of the Middle Ages. The text is attributed either to Abū Ma'sar (787-886) or to his pupil Ibn al-Bāzyār, and was translated into Latin in the mid-twelfth century. In eight books (parts) it provides the scientific basis for predictions concerning kings, prophets, dynasties, religions, wars, epidemics etc., by means of conjunctions of planets, comets and other astronomical factors. It is cited frequently by both Arabic and Latin authors. These editions will provide, for the...